This invention relates to a flexible pipe connector for interconnecting lengths of corrugated pipe and creating a water-tight gravity flow seal between the lengths of corrugated pipe, or with use of a suitable fastener, to create a water-tight pressure seal connection. In addition, the invention can be adapted to have a male and female end so that the female end can receive a length of corrugated pipe and the male end can be inserted into a flexible seal member used with septic system and drainage components, the male end being further adapted to receive in its inner diameter a leveling device. Alternatively, the male end can be inserted into a smooth-walled hard plastic fitting (PVC, ABS, or the like), such as a "T" or elbow fitting, for example. Also, a female-to-female version of the subject invention can be used to sealably connect abutting ends of smooth-walled, hard plastic pipe.
Currently, corrugated plastic pipe is widely used for farm field drainage, septic systems, drain tiles, and many other similar uses. Corrugated plastic pipe, such as the so-called 1500 lb. crush corrugated pipe, for example, is relatively inexpensive and can be obtained commercially in straight lengths, normally 10 feet long, or in rolls of up to 100 or more feet. Also, while plastic corrugated pipe is normally sold in a 4" diameter size, it is also available in other diameters, such as from 2" to 36", for example.
Some corrugated plastic pipe is sold with perforations or holes formed along the longitudinal length of the pipe so that water, sanitary effluent, or other fluids carried in the pipe can seep out of the perforations or holes so as to drain the same, such as into associated septic leach fields. Although corrugated pipe with such perforations or holes is widely used, non-perforated corrugated pipe is also used for a wide variety of applications for which perforated corrugated pipe would not be appropriate. As an example, farmers needing to drain low spots in a field need a water-tight corrugated pipe to provide a means for communicating water from the low spots to a distant drainage area. Also, there are many areas where local zoning codes would allow use of non-perforated corrugated pipe for septic systems, if only a suitable sealed coupler were available. Although corrugated plastic pipe is relatively inexpensive and easy to obtain, there are few known couplers for providing a water-tight seal, and what water-tight couplings are available are relatively expensive in comparison to the cost of corrugated plastic pipe.
One known coupler used for forming a fluid-tight seal includes an annular sealing gasket which fits into one or more grooves at the end of each piece of corrugated pipe. After such a sealing gasket is placed on each end of corrugated pipe, each pipe end is placed into a hard plastic cylindrical connector to produce a relatively water-tight seal. Such a known connector, including the two rubber gaskets and a hard plastic cylindrical connector, is quite expensive when compared with the cost of corrugated pipe. Additionally, this connector requires the installer to work each rubber gasket over each end of corrugated pipe until it is received in one or more grooves on the outer diameter of the corrugated pipe. Then, the user must force each end of the corrugated pipe into the hard plastic connector. This operation requires a multitude of steps which may be difficult to perform in the field and require an unwarranted expenditure of time.
Another coupling for forming a fluid-tight seal provides a heat-shrinkable sleeve as disclosed in U.S. Pat. No. 4,141,576. That heat-shrinkable sleeve has a pipe end placed in each end thereof and is then shrunk via application of heat onto the abutting end portions of the pipes to create a frictional engagement between each section of pipe. The heat-shrinkable sleeve is made of a thermoplastic material having elastic memory so that when it is heated, it shrinks to relieve stresses which were introduced into the sleeve during manufacture, i.e., it will not resume its original shape. Although this known coupling provides a fluid-tight seal, the heat-shrinkable sleeve is relatively difficult and expensive to manufacture, requires the performance of a heat-shrinking operation which may be difficult in many field situations, and requires an expense in excess of the cost of the corrugated pipes being connected.
Other means for connecting lengths of corrugated plastic pipe are known in the art, however, these means often do not effectuate a water-tight seal between the lengths of corrugated pipe. One such coupling has a generally cylindrical body and a mouth at both ends for receiving the ends of pipe to be connected. The inner circumference of the cylindrical body has a plurality of deflectable cleats for engaging the outer corrugations of the corrugated pipe so that the pipe is longitudinally retained in the mouth of the coupling. This type of coupling is formed of relatively rigid plastic material, is relatively expensive, and does not provide a water-tight seal, i.e., it does not closely conform to the corrugated pipe's outer surface in use. For an example of such a coupling, reference may be had to U.S. Pat. No. 3,695,643.
Another device known in the art for innerconnecting lengths of corrugated pipe is to provide an internal coupling structure having a plurality of integrally molded cleats extending generally radially outward from the surface of the coupler to engage the inner corrugations of the length of corrugated pipe. Such a coupling structure is relatively expensive, is difficult to use in the field and again does not provide a fluid-tight seal between the lengths of corrugated pipe as it is substantially rigid. For an example of such an internal coupling structure, reference may be had to U.S. Pat. No. 4,247,136.
In addition to being used to interconnect lengths of corrugated pipe, the flexible pipe connector of the present invention can be used to connect lengths of so-called dual-wall co-extruded pipe. Such dual-wall co-extruded pipe normally has an outer corrugated diameter and an inner smooth diameter with a hollow space existing between the inside of the corrugation and the outside of the inner smooth wall. This type of pipe is normally sold in 10-foot straight lengths, in diameters from 4" to 36" or more, and is often used as a substitute for the well known smooth wall PVC pipe. This is because such dual-wall co-extruded pipe is more advantageous as it provides the strength of PVC pipe, but is usually less expensive as it does not require as much material since the space between the corrugations and the inner wall is hollow. Currently, dual-wall co-extruded pipe is connected in a water-tight seal by using a gasket or O-ring on each end of pipe to be insertably engaged into a hard plastic coupling, similar to the corrugated fitting noted above. However, such a coupling is relatively expensive especially when used with dual-wall co-extruded pipe. Since the latter is only sold in 10-foot or 20-foot lengths, an expensive coupling is required every 10 feet, which expense limits the applications for such dual-walled pipe.